Robust quantitative groundwater maps for Africa were developed to highlight areas more likely to be resilient to climate change and also where sufficient groundwater resources may be available to help adaptation.
The maps are the first produced for Africa and are underpinned by dedicated case studies and systematic data/literature reviews.
Download the Quantitative maps of groundwater resources in Africa article published in Environmental Research Letters.
To understand and characterise the resilience of African groundwater to climate change requires an understanding of the spatial distribution of groundwater storage, aquifer permeability and the annual rate of recharge.
In groundwater science this means characterising:
Quantitative data on transmissivity and effective porosity are scarce for much of Africa, and a series of proxies for these parameters were used instead which have been found to be an effective surrogate in data poor areas elsewhere (e.g. Graham et al., 2009):
The methodology used to develop the quantitative groundwater maps (aquifer productivity, aquifer flow/storage type, and saturated aquifer thickness) is shown in Figure 2.
Every effort was made to use all available information, including:
The final drafts were sent for peer review to experts in African groundwater.
The maps indicate:
The maps have been developed using the best available data at a continental scale for Africa; Figure 2 illustrates the extent of available data and confidence in the resulting maps.
The lack of good quality hydrogeological maps in North and West Africa is compensated for by the availability of many individual studies, which vary from local to regional scale. In Central Africa, however, both maps and study information are scarce.
The maps are designed to show information at the continental, or regional scale (i.e. to be used at a nominal scale of approximately 1:20 m). Their primary aim is to highlight:
They should not be used for national planning. The approach could be repeated for individual countries, but would require more detailed geological and hydrogeological information.
Contact Dr Alan MacDonald, Project Leader, for further information